31051020857 has 2 divisors, whose sum is σ = 31051020858. Its totient is φ = 31051020856.

The previous prime is 31051020797. The next prime is 31051020877. The reversal of 31051020857 is 75802015013.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21494785321 + 9556235536 = 146611^2 + 97756^2 .

It is an emirp because it is prime and its reverse (75802015013) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31051020857 - 2¹⁰ = 31051019833 is a prime.

It is not a weakly prime, because it can be changed into another prime (31051020877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15525510428 + 15525510429.

It is an arithmetic number, because the mean of its divisors is an integer number (15525510429).

Almost surely, 2^31051020857 is an apocalyptic number.

It is an amenable number.

31051020857 is a deficient number, since it is larger than the sum of its proper divisors (1).

31051020857 is an equidigital number, since it uses as much as digits as its factorization.

31051020857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8400, while the sum is 32.

The spelling of 31051020857 in words is "thirty-one billion, fifty-one million, twenty thousand, eight hundred fifty-seven".